1. Field of the Invention
The present invention relates to an imaging system that captures an image of a subject and acquires digital image data, and to a control method of the imaging system.
2. Description of the Related Art
In the field of pathological diagnosis, imaging systems that capture a microscope image of a subject specimen (a tissue slice or the like of a human body) to acquire, store, and view a high-definition digital image are recently gaining prominence. An imaging system of this type is also referred to as a virtual slide system.
Japanese Patent Application Laid-Open No. H09-281405 proposes a system that enables wide-field observation by piecing together a plurality of images of different imaging blocks in order to generate a high-resolution, wide angle-of-view image. In this system, after an operator first specifies an imaging area on a low-resolution entire image, an image processing apparatus divides the imaging area into blocks, captures a high-magnification image of each block using a microscope, and pieces image data of the respective blocks together to generate a single image. In addition, Japanese Patent Application Laid-Open No. 2000-295462 discloses automatically detecting a range (a top-left coordinate and a bottom-right coordinate) in which a specimen image exists among an entire image based on brightness information, and dividing the detected range into blocks and capturing a high-magnification image of each block using a microscope. As described above, watching a specimen position or a range to be observed on a slide glass before acquiring a high-resolution image has been conventionally performed.
However, conventional systems simply divide a specified (designated) or detected imaging area in a mechanical manner based on a size that can be acquired by one imaging operation.
Therefore, there may be cases where a portion in which an image changes abruptly such as a contour or an irregularity of a specimen image overlaps with a boundary between blocks. In such a case, since features (brightness, color, contrast, or the like) of the image varies significantly at a joint between images of blocks, an image merging process may become complicated or difficult or a required processing time may increase. There is also a risk that many of the joints of images may become discontinuous.